Progressive symmetric erythrokeratoderma (PSEK) is a genetic condition featured by the appearance of symmetrically distributed demarcated hyperkeratotic plaques, often with associated palmoplantar hyperkeratosis, with new plaques developed over time. Previously mutation in two genes LOR and GJB4 have been implicated with PSEK, while a locus for PSEK has been mapped to 21q11.2-q21.2. In this study we identified a homozygous frameshift deletion (c.811delA; p.Ser271fs) in KRT83 gene that leads to PSEK. Heterozygous missense substitutions in KRT83 have been implicated in autosomal dominant monilethrix. Our study thus indicates that at least some cases of autosomal recessive PSEK and autosomal dominant monilethrix are allelic, respectively resulting from loss-of-function and missense mutations in the KRT83 gene. (By Dr. Khadim Shah, http://jmg.bmj.com/content/early/2016/12/13/jmedgenet-2016-104107 )